Electromagnetic valve

ABSTRACT

An electromagnetic valve including a splined or other similar external adjustment member for setting a valve member location on the armature, or spring pressure on the armature.

United States Patent Putschky Apr. 8, 1975 1 1 ELECTROMAGNETIC VALVE[56] References Cited [75] Inventor: Ernst Heinrich Putschky, UNITEDSTATES PATENTS Reichenbach. Germany 3.114.532 12/1963 Gray et al.251/129 X 3.250.293 5/1966 Adams et a1 251/129 X [731 Ass'gmi2 New3.381.931 5/l968 Boonshaft et a1 251/129 x 3529.620 9/1970Lieber.........1........ 251/129 x y 3,531,080 9/1970 D1110" 251/129 [2PP 78 Primary Examiner-Arnold Rosenthal Attorney, Agent. or F1'rmA.Donald Stolzy [30] Ma e ri r n z ri Prioriy Data 2222448 [57] ABSTRACT yy An electromagnetic valve including a splined or other [52] us Cl.251]29, 251/139 similar external adjustment member for setting a valve[511 11.. c1..11111111111111111111111111111111 F161 31,06 memberlocation on we armature or spring {58] Field of Search 251/129, 139armame- 2 Claims, 3 Drawing Figures ELECTROMAGNETIC VALVE BACKGROUND OFTHE INVENTION This invention relates to fluid flow control devices, andmore particularly, to a solenoid valve or the like wherein the armatureof an electromagnet, when energized, urges a valve member onto or off ofa valve seat.

Prior art valves are often used in hydraulic device and pressureregulator applications Using such devices, pressure regulation and flowrate control may be accomplished by controlling the voltage impressedacross the electromagnetic winding. In contrast to other prior art arevalves wherein the valve was separated from the electromagnet and amechanical connection had to be first established by a resilientintermediary member, the said other prior art valves were integrallyformed. This was true because the valve member formed a spacer betweenthe armature and the yoke. The spacer established an air gap. It is truethat this arrangement does not make maximum use of the force of theelectromagnet. On the other hand, this method permits positive controlof the discharge pres sure or of the amount of discharge pressuremedium, respectively, because it is by means of the high magneticreluctance in the air gap that operation in the lower area of theelectromagnets travel/force characteristic is possible. Within the saidlower area, the tra vel/force characteristic curve runs approximately inparallel to the travel axis. This results in always welldefinedtravel/force intersection points following each other in an almostlinear sequence under varying degrees of energization of theelectromagnet. This method also avoids the need for a spring between thearmature and the valve member, required previously. In the said othervalve, the pressure of the valve member bearing upon the valve seat wasdetermined exclusively by the electromagnetic field strength. Thus, ifthe magnet were suitably designed, the said field strength varied inproportion to the voltage applied to the electro-magnet.

When manufacturing the said other valves, there were only two points tobe observed regarding the travel/force characteristic:

l Observance of a given air gap; and

2 Adequate design of the electromagnet.

If the air gap were too small, the valve would operate within the rangeof an already considerably curved characteristic; and if it were toolarge, the electromagnetic force would not suffice to control the valvein accord with the given characteristic.

If the design of the electromagnet were inadequate, i.e. if theelectromagnetic field were too strong, the valve would operate withinthe range of an already considerably curved characteristic, and if itwere too weak, the electromagnetic forces would not be sufficient tocontrol the valve.

A conventional electromagnetic valve may sometimes be designed withoutgreat difficulty; however, difficulties may arise when an attempt ismade to fabricate a valve with an air gap defined between very closetolerances.

SUMMARY OF THE INVENTION In accordance with the device of the presentinvention, the abovedescribed and other disadvantages of the prior artare overcome by providing a valve by which the air gap can be adjusted.

The present invention thus avoids the necessity for high precisionmanufacture of the prior art electromagnetic valve, that is, forexample, the fabrication of such a valve with a yoke-to-armature spacingbetween very close tolerances. It will be understood that with gapadjustment, neither manufacture nor operation is restricted.

According to the present invention, air gap adjustment is achieved byinserting the valve member into the armature via longitudinallyadjustable members. In this case, the valve member is preferablyinserted into a bore in one end of the armature and is longitudinallymovable therein, a tapped hole with an adjusting screw engaging with thesaid bore from the end of the armature opposite the said one endthereof. The valve member is supported by the one end of the adjustingscrew so that it is possible for the said screw to urge the valve memberout of the armature.

If the armature of the electromagnetic valve of the present invention isconstructed in the manner described, the valve member can be quicklyinserted following armature manufacture and be adjusted outside theelectromagnet later on.

The present invention also provides for an adjusting opening that can beclosed in the cover of the electromagnet resting against the armatureand through which opening an adjusting screw can be seized and turned.

It is also possible to provide in the electromagnets cover restingagainst the armature a pin longitudinally movable and at one end beingconstructed in the form of a tool adapted to seize the adjusting screwand projecting into the tapped hole of the armature. This is anadvantage in that the electromagnetic valve can be adjusted orreadjusted, when pressure is applied, i.e. during operating conditions.

Prior art valves are troublesome in use because the valve member thereofoften came loose and reduced the speed of response of the valve. Thevalve of the present invention also overcomes this problem because thevalve member thereof is connected firmly although rotatably with theadjusting screw so as to enable the valve member to follow axialadjusting-screw movement.

To avoid turning of the armature when the adjusting screw is turned, theformer is suitably secured. It is conventional practice in prior artelectromagnetic valves to provide in the armature, with the armaturechamber filled with fluid, a damp armature motion. In accordance withthe valve of the present invention, a guide pin engaging with the saidbore is inserted into the cover resting against the armature. Thisavoids the need for additional means or bores and provides a simple andinexpensive mechanism for preventing the armature from rotating.

The above-described and other advantages of the present invention willbe better understood from the following detailed description whenconsidered in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings which are to beregarded as merely illustrative:

FIG. 1 is a longitudinal sectional view through an electromagnetic valveconstructed in accordance with the present invention.

FIG. 2 is a longitudinal sectional view through an armature of a secondembodiment of the present invention; and

FIG. 3 is a longitudinal sectional view through a third embodiment ofthe present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawings, in FIG. 1, anelectromagnetic valve, including an electromagnet l, is illustratedincluding a hollow, cylindrical working chamber surrounding an armature2 which may be filled with a fluid.

Armature 2 is longitudinally movable with a ball 3 serving as a valvemember. Said working chamber also includes a valve body 4 with inlet 5and exhausts 6. The exit portion of the inlet 5 where it leaves thevalve body 4 is constructed as a valve seat seating the ball 3 as thevalve member when the valve is closed. On the other side, the workingchamber of the electromagnet l is sealed by a cover 8 through whichthere is extending a pin 17. Mounted on the magnet is also aconventional plug-in unit 9 to supply current to the electromagnet I.

The ball 3 is confined within a bore 10 of the armature 2. Said ballrests against the front end of an adjust ing screw 11 containing acentral tapped hole 12 of the armature 2. In engagement with saidadjusting screw 11 is a leafshaped extension 13 of the pine I7permitting the adjusting screw II to be turned from the outside throughsaid pin 17. This results in the ball 3 being forced out of or into thebore 10 in the armature 2 OS that it is possible to adjust the air gap14 between the front ends of the valve body 4 serving as the yoke andthe armature 2.

In order to always obtain a defined valve member position, the valvemember is firmly, yet rotatably, connected with the adjusting screw ll.As shown in FIG. 2, this can be achieved by threading a bushing 15 intoa ball 23 serving as a valve member, with an adjusting screw 11'projecting into said bushing. The end of the adjusting screw 11'includes a collar 16 behind which there are situated two slotted pins 18passing through the bushing 15. In this case, the ball 23 is firmly connected with the adjusting screw 11' without, however, impairing itsrotation.

Furthermore, FIG. 2 shows an eccentric bore 19 passing through thearmature 2 and containing a damping nozzle 20. A guide pin 21, e.g.press fit into the cover 8 projects into said eccentric bore 19 intowhich it is slidable. Guide pin 21 thus prevents an armature 2 fromrotating when the adjusting screw is turned.

In contrast to the progressively acting electromagnetic valve shown inFIG. 1, FIG. 3 shows a degressively acting electromagnetic valve wherethe valve will be opened when a voltage is applied to the electromagnet.This embodiment, too, permits adjustment of the air gap between a yoke22 and an armature 2" in the previously described manner, i.e., by meansof an adjusting screw 11". This embodiment does not require the valvemember to be connected with the adjusting screw 11". In this embodiment,the valve member 3 will always be urged back onto the valve seat by theforce of a spring 24. In the electromagnetic valve.

shown it is furthermore possible to change the contact pressure threougha hexagon socket screw 25 in such a way that after removal of a sealingscrew 27 in the cover 8, it will be possible to pass a tool through theopening thus created and through the bore 26 to permit turning of theadjusting screw 11''. At the same time, the screw 25 can also be turnedif so required, thus causing the contact pressure of the spring 24bearing on the armature to be changed.

What is claimed is:

1. A valve assembly comprising: first means defining a chamber; aferromagnetic armature guided for movement in said chamber; a member insaid chamber mounted on said armature, said member being adjustable infirst and second directions to move said member in third and fourthdirections, respectively, relative to said armature; a body mounted onsaid first means providing a valve seat having an inlet openingtherethrough; a solenoid-like winding fixed relative to and around saidfirst means in a position to cause, when energized, movement of saidarmature from a first position thereof to a second position thereof; andsecond means movable with said member to abut said valve seat and toclose said inlet opening, abutment of said second means with said valveseat taking place when said member is in a predetermined position, theposition of said armature relative to said valve seat when said abutmenttakes place being changeable by adjustment of said member, said firstmeans including a plate having a hole extending completely therethrough,a shaft rotatable in said plate hole having one end in engagement withsaid member to rotate the same therewith and to adjust the same by saidrotation.

2. The invention as defined in claim 1, wherein the other end of saidshaft has a construction to permit en gagement therewith by a tooladapted to rotate the same.

1. A valve assembly comprising: first means defining a chamber; aferromagnetic armature guided for movement in said chamber; a member insaid chamber mounted on said armature, said member being adjustable infirst and second directions to move said member in third and fourthdirections, respectively, relative to said armature; a body mounted onsaid first means providing a valve seat having an inlet openingtherethrough; a solenoid-like winding fixed relative to and around saidfirst means in a position to cause, when energized, movement of saidarmature from a first position thereof to a second position thereof; andsecond means movable with said member to abut said valve seat and toclose said inlet opening, abutment of said second means with said valveseat taking place when said member is in a predetermined position, theposition of said armature relative to said valve seat when said abutmenttakes place being changeable by adjustment of said member, said firstmeans including a plate having a hole extending completely therethrough,a shaft rotatable in said plate hole having one end in engagement withsaid member to rotate the same therewith and to adjust the same by saidrotation.
 2. The invention as defined in claim 1, wherein the other endof said shaft has a construction to permit engagement therewith by atool adapted to rotate the same.